Electric service plug with prongs in cap



Nov. 20, 1934. A. s. MCCLOY HAL 1,981,458

ELECTRIC SERVICE PLUG WITH PRONGS IN CAP Filed Jan. 3, 1933 INVENTORS flier/10,83 M 620). Aj' A LEVFikENCI-I.

ATTORNEYS Patented Nov. 20, 1-934 UNITED STATES PATENT OFFICE PLUG WITH PRON GS ELECTRIC SERVICII'IIQ Application January 3, 1933, Serial No. 649,994 7 Claims. ;(Cl. 173-361) In a copending application Serial No. 618,714, we have described an electric service plug adapted for use in leading electric current to various household appliances, the plug therein disclosed 6 comprising essentially a base and resilient closure cap, the base carrying terminal prongs adapted to extend or be disposed at an angle of substantially or approximately 90 to the conductor cord. The present invention is'in part a continuation l and is in part an improvement over the invention disclosed in our prior application. An important distinction, however, is that in the instant invention the terminal prongs are secured to the closure cap, whereas in the embodiment of the invention illustrated in our former application the prongs were secured to and carried by the base of the plug.

Thepresent invention will be fully apparent from the following detailed disclosure and will be pointed out with particularity in the appended claims.

In the drawing forming part of our disclosure:

Fig. 1 is a side elevation of a plug embodying our invention;

Fig. 2 is a view from the right side of Fig. 1 on a larger scale, the cap portion of the device being broken away;

Fig. 3 is an inverted plan of Fig. l;

Fig. 4 is a section on line 44 of Fig. 1;

Fig. 5 is a detail face view showing the base of the improved plug;

Fig. 6 is a detail section through the base taken on line 6-6 of Fig. 5;

Fig. 7 is a detail section through the cap of the Fig. 8 is a perspective view showing the cap, terminal prongs and key piece before assembly;

Fig. 9 is a plan view of the key piece adapted to hold the prongs in place.

Referring in detail to the drawing, 10 represents generally the base of the plug. This may be formed of moldable insulating material, which in the present instance may be rigid such as hard rubber, bakelite, or the like, or it may be of live rubber possessing a limited degree of resiliency. This base is formed with an extension or branch 12 having a side opening 14 therein, for the entrance of a conductor wire 16, this opening communicating with an interior chamber 18, adapted to enclose the bared ends of the conductor wire, which are secured to the terminal prongs 20 of the plug. These terminal prongs extend through slots 22 formed in the end wall 24 of the base.

The base has a shell-like wall 26 on the extremity flange 28 of the base.

The terminal prongs 20, at their extremities, are each bent at an angle to form an anchorage lug 36. Each lug is adapted to be fitted into a notch 38 branching from a central key socket 40. A key piece 42 is provided, which has a substantially cylindrical portion 44 of a size to make a snug fit with the key socket 40. This key piece is formed at diametrically opposite points with recesses, one of which is shown at 46 in Fig. 8. Each recess 46 is of a size to fit the respective prong 20. When the partsare properly assembled, the lugs 36 are secure'y held in the notches 38 by the key piece 42, as will be apparent from examination of Fig. 4. 'The key piece has an extended barrier portion '48. prong 20 is provided with a suitably threaded aperture for the reception-of a terminal screw 50 and the prongs are provided with ears or projections 52, properly confining the bared ends of the conductors, which are adapted to be connected to the prongs by the terminal screws. The parts are so designed and proportioned that the barrier portion 48 of the key piece projects between the prongs 20-20 and their respective terminal screws 50-50.

The embodiment of the invention described provides a construction which can be readily and inexpensively assembled, yet when once assembled the parts are securely held and are not likely to work loose, nor can the plug be readily rendered inoperative by being dropped or struck with hard objects, such as articles of furniture.

To assemble the parts, it is merely necessary to insert the lugs 36 of the prongs in the notches 38 and then slip the key piece 42 into the-recess 40 of the cap. This key piece is preferably made of rubber, or similar insulating material. Regardless of what material it is made, it preferably makes a tight fit with the prongs as well as with the socket 40 in the cap. Thus, this key piece serves the double function of holding the prongs in place and also that of a barrier between the While in practice, the key piece 42 is adapted to remain in the position illustrated in Each terminal 1,9s1,4ss

Fig. 4. It is noted that the proportion of the parts is such that it cannot get out oi place because the endwise movement thereof would be limited by the end wall 24.

In wiring up the plug, the wires are passed through the opening 14, then knotted in a conventional manner and secured to the prongs by the screws; 50; The prongs are then pushed through the slots 22 in the body, the wire 16 being pulled back through the opening 14 to take up the slack. The annular flange 32 of the cap is then tensioned over the bead 28 of the base, thus completing the assembly.

While we have described quite precisely certain characteristic features of the invention herein illustrated it is not to be construed that we are limited thereto since various modifications may be made by those skilled in the art without departing from the invention as defined in the appended claims.

What we claim is:-- s

1. An electric service plug comprising a chambered base having an end wall slotted for the passage of terminal prongs, an annular side wall with a conductor opening therein, an imperforate closure cap secured to-the base and having a prong cavity with lateral notches formed therein, terminal prongs, parts of which extend through the end wall of said base and having lugs seated in said lateral notches and a key piece seated in said cavity and holding said terminal prongs in place.

2. An electric service plug comprising a chambered base having a slotted end wall, an annular side wall with a lateral conductor opening therein, a cap of resilient material tensioned over said base carrying a pair of terminal prongs, which project through the slots in the base and a single key for interlocking the pair of terminal prongs with said cap.

3. A service plug comprising a chambered base having a slotted end wall, an annular side wall with a lateral conductor opening therein, a cap of resilient material tensioned over said base carrying terminal prongs which project through slots formed in the base, a lug on each of said prongs and a key for interlocking said lugs with said cap, terminal screws carried by the prongs and a barrier member secured to said key piece and disposed between said terminal screws.

4. A service plug comprising a base having an end wall slotted for the passage of terminal prongs, and a side wall having a lateral conductor opening therein, a closure cap secured to the extremity of the side wall remote from said end wall, terminal prongs carried by said cap and extending longitudinally through the end wall of the base and conductors secured to said prongs and extending substantially at right angles thereto through said lateral opening, said closure cap being formed of resilient material tensioned over said side wall, and a key piece seated in the cap effective to secure the terminal prongs therein.

5. A service plug comprising a base having an end wall slotted for the passage -of terminal prongs, a side wall apertured for the passage of a conductor, a closure cap of resilient material tensioned over the side wall, said terminals having angularly disposed portions interengaged with notches formed in said cap and akey piece seated in the cap effective to hold the angularly disposed portions in said notches.

6. A service plug comprising a chambered base having an end wall slotted for the passage of terminal prongs, a shell-like side wall apertured for the passage of a conductor, a cap of resilient material tensioned over said base, a pair of terminal prongs having angularly disposed portions seated in notches formed in said cap, a key piece fitted to the cap and having recessed portions for engagement with the terminal prongs.

7. A service plug comprising a chambered base having an end wall slotted longitudinally for the passage of terminal prongs, a shell-like side wall apertured laterally for the passage of a conductor, a cap of resilient material tensioned over said base, a pair of terminal prongs extending longitudinally through said end wall and having angularly disposed portions seated in sockets formed in said cap, a key piece fitted to the cap and having recessed portions for engagement with terminal prongs, said key piece having a barrier disposed between the terminal prongs and extending into the chambered portion of said base.

I ARTHUR S. MCCLOY.

STANLEY F. FRENCH. 

